Merge plainbox-provider-checkbox:phlin/code-style-fix into plainbox-provider-checkbox:master

[Po-Hsu Lin]

This patch will:
1. move report_failures() to main(), remove unnecessary parentheses

   The report_failures() is now just return whether the test pass or fail
   move the code piece to main() and update the docstring accordingly.

2. remove extra print for kernel taint info
   The tainted bit value and its message will be printed at the beginning
   of this if statement, there is no need to print it again.

3. Use raise SystemExit() for taint_file not found exeception.

[Maciej Kisielewski (kissiel)]

Thanks for the cleanup!

Some time ago we introduced a guideline for contributions to checkbox and its family. We started using prefixes for what the commit does, so it's easier to create relnotes and overall navigate through the repos.
"""
In addition, if it makes sense to do so, prefix the title with one of the following terms:
Add
Change
Remove
Fix
"""
If you could be so kind and amend the commits with prefix like that it would be awesome.

There's also one thing I highlighted in the diff below. Feel free to not do anything about it :D

[Po-Hsu Lin (cypressyew)]

Hi Maciej,
Thanks for the review, I have the title amended and these 2 commits squashed into 1, with your inline diff suggestion included. Please find the resubmitted MP.
Thanks!
Sam

[Maciej Kisielewski (kissiel)]

Thank you very much!
Looks good! +1

review: Approve

diff --git a/bin/kernel_taint_test.py b/bin/kernel_taint_test.py
index 2ee70c1..677d127 100755
--- a/bin/kernel_taint_test.py
+++ b/bin/kernel_taint_test.py
@@ -44,10 +44,10 @@ def find_taints(taint_file):
         f = open(taint_file, "r")
         taints = int(f.read())
     except OSError:
-        taints = -1
-        print("Kernel taint file ({}) not found!".format(taint_file))
+        raise SystemExit(
+            "Kernel taint file ({}) not found!".format(taint_file))
     print("Kernel taint value is {}".format(taints))
-    return(taints)
+    return taints
 
 
 def get_modules():
@@ -57,7 +57,7 @@ def get_modules():
     for line in lsmod_output:
         if line and 'Module' not in line:
             modules.append(line.split()[0])
-    return(modules)
+    return modules
 
 
 def process_out_of_tree_modules(modules):
@@ -68,7 +68,7 @@ def process_out_of_tree_modules(modules):
         if not check_output(shlex.split(cmd),
                             universal_newlines=True):
             mod_list.append(mod)
-    return(mod_list)
+    return mod_list
 
 
 def process_GPL_incompatible_modules(modules):
@@ -80,7 +80,7 @@ def process_GPL_incompatible_modules(modules):
                                universal_newlines=True).strip()
         if "GPL" not in license and "MIT" not in license:
             mod_list.append((mod, license))
-    return(mod_list)
+    return mod_list
 
 
 def remove_ignored_modules(modules):
@@ -98,11 +98,18 @@ def remove_ignored_modules(modules):
             modules.remove(ignore_mod)
         except ValueError:
             pass
-    return(modules)
+    return modules
 
 
-def report_failures(taints):
-    """Report the failure code and its meaning(s)."""
+def main():
+    """Print out the tainted state code and its meaning(s)."""
+    parser = ArgumentParser()
+    parser.add_argument('--taint-file',
+                        default="/proc/sys/kernel/tainted",
+                        help='The file that holds the taint information')
+    args = parser.parse_args()
+    taints = find_taints(args.taint_file)
+
     # Below meaning strings are taken from
     # https://www.kernel.org/doc/html/latest/admin-guide/tainted-kernels.html
     taint_meanings = ["proprietary module was loaded",
@@ -151,8 +158,8 @@ def report_failures(taints):
                     print("*   Out of Tree modules found, "
                           "but they are expected and OK")
             else:
-                print("Taint bit value: {} ({})".format(i, taint_meanings[i]))
                 count += 1
+
     if count == 0:
         # else case below contains expected issue in case 0 / 11 / 12
         if not taints:
@@ -162,18 +169,5 @@ def report_failures(taints):
         return 1
 
 
-def main():
-    parser = ArgumentParser()
-    parser.add_argument('--taint-file',
-                        default="/proc/sys/kernel/tainted",
-                        help='The file that holds the taint information')
-    args = parser.parse_args()
-    taints = find_taints(args.taint_file)
-    if taints < 0:
-        return taints
-
-    return(report_failures(taints))
-
-
 if __name__ == '__main__':
     sys.exit(main())